How is Personality Studied and Assessed?

Friedman & Schustack p.24 -61

• Objective Assessment

• Measurement that is not dependent on the individual making the assessment

• Subjective Assessment

• Measurement that relies on interpretation by the individual making the assessment (p.25)

Measuring Personality

• Reliability• The consistency of scores that are

expected to be the same (similar scores on different occasions)

• Test-Retest Reliability• The degree of consistency between the

results of the same test taken on different occasions

• Internal Consistency Reliability• Degree of consistency between subparts or

equivalent parts of a test (i.e. split half reliability)

• Error Variance• Variations of a measurement that are the result

of irrelevant, chance fluctuations (i.e. humidity in spring and winter)

• How can we have a reliable assessment of personality if personality may change?

• - pattern• - long term (after a major trauma)

• Validity• The extent to which a test measures what

it is supposed to be measuring

• Construct Validity• The extent to which a test truly measures

a theoretical construct (assessment predict behavior and reactions implied theoretically by the construct)

• Convergent Validation• The extent to which an assessment is related to

what is should be related to

• Discriminant Validation• The extent to which an assessment is not

related to what it should not be related to

• Criterion-Related Validation• The extent to which an assessment predicts

outcome criteria that were produced by different assessment methods (i.e. who is likely to be a leader)

• Multitrait-Multimethod perspective• The use of multiple assessment methods

and various traits in order to determine test validity

• Content Validity• The extent to which a test is measuring

the domain it is supposed to be measuring (creative ability vs artistic ability)

• Item Selection – clear, relevant & simple

• Item intercorrelation• The extent to which test items are related to one

another (useful distribution – full range of individual)

• Item Response Theory (IRT)• A mathematical approach to choosing test items

in which the probability of a positive response to an item is determined by the person’s estimated position on the underlying trait being measured, as well as by characteristics of the item (choose the best item)

Bias

1. Response Sets

2. Ethnic Bias

3. Gender Bias

• Response Sets• A bias responding to test items that is unrelated

to the personality characteristic being measured

• Acquiescence Response Set• A bias in which people are more likely to agree

than disagree with anything that is asked of them

• Social Desirability Response Set• A bias in which people are likely to want to

present themselves in a favorable light or to try to please the experimenter or test administrator

• Ethnic Bias

• A type of bias in which a test fails to take into account the relevant culture or subculture of the person being tested

• Gender Bias (i.e problem with women vs job discrimination, lack of equal ed. Opportunity – environmental factors)

Varieties of Personality Measures• Self-Report Tests• Minnesota Multiphasic personality Inventory

(MMPI) – A comprehensive, self-report personality test that is focused on assessing psychopathology

• NEO Personality Inventory

• Factor Analysis • A statistical technique in which correlations

among a number of simple scales are reduced to a few basic dimensions

• Personality Research Form (PRF)

• A self-report test that assesses needs by forced responses to short, standardized items

• Myers-Briggs Type Indicator (MBTI) – Carl Jung’s Type theory

• Q-Sort Test

• A method of personality assessment in which a person is give a stack of cards naming various characteristics and is asked to sort them in to piles

• Biological Measures• Phrenoligy – feeling the position and shapes of

bumps on people’s skull• Electroencephalograms (EEGs) – measure

electrical potentials at the scalp that are caused by large populations of neurons becoming active simultaneously

• Positron emmision tomography (PET)• Scan to show brain activity by recording the

brain’s use of radioactive glucose

• Functional magnetic resonance imaging (fMRI) – assesses brain activity by measuring changes in oxygenated blood flow, as blood flow will be directed to regions of the brain where activity is highest

• Behavioral Observations

• Experience Sampling method of Assessment – A method in which participants record their current activity or thought processes when they are paged by the experimenter at various intervals during the day

• Interviews

• Psychotherapeutic Interview – An interview in which a client talks about the important or troubling parts of his or her life

• Structure Interview – A systematic interview in which the interviewer follows a definite plan so that similar types of information are elicited from each interviewee

• Typology – a categorical scheme in which a person is a member of only one of a small set of groups

• Expressive Behavior – a term used to describe nonverbal social skills such as vocal characteristics, facial expressions, body gestures, and movements

• Document Analysis and Life Stories - a method of assessing personality by applying personality theories to the study of diaries, letters, and other personal records

• Projective Tests – an assessment technique that attempts to study personality through use of a relatively unstructured stimulus, task, or situation – A Rorschach-Type inblot; Thematic Apperception Test (TAT) – make up a story about a picture that is presented

• Demographics and Lifestyle

• Demograhphic Information – information relevant to population statistics such as age, cultural group, place of birth, religion, and the like

• Is there one best method of assessment?

• - the person

• - the assessor

• - the purpose of the assessment

• The weakness in one assessment technique can be compensated for by other techniques

• The Design of Research

• - Case Studies

• - Correlational Studies

• - Experimental Studies

• Case Study Design – A research method that involves an in-depth analysis of a single individual

• Correlational Studies – Studies in which the degree of relationship between two variables (or among multiple variables) is assessed

• Experimental Studies

• Control group – a comparison group that provides a standard by which to evaluated a theory or technique